The selective control of weeds is a constant problem in crop production around the world. In particular the control of monocotyledenous weeds when growing in the presence of monocotyledenous crops such as cereal crops is burdensome. Not only do said weed species tend to proliferate under the same or similar cultivation conditions in which cereal crops flourish, but in addition, the very herbicidal agents which are most effective for controlling these weeds, also tend to cause harmful phytotoxic effects to cereal crop plants. Therefore, new effective methods for the selective control of unwanted monocotyledenous weeds in cereal crop production are continually sought.
It is an object of this invention to provide methods for the effective control of monocotyledenous weeds in the presence of crop plants, including monocotyledenous crop plants, without undue harm to said crop plants.
It is a further object or this invention to provide 4-(2,6-disubstituted-phenoxy)coumarin derivatives, useful as selective herbicides in crop production and particularly in cereal crop production.
It is an advantage of this invention that the 4-(2,6-disubstituted-phenoxy)coumarin derivatives are particularly effective for controlling grass and other monocotyledenous weeds under flooded paddy rice application conditions while having little or no phytotoxic effects on the rice crop.